Issue advocacy advertising, the weapon of choice by interest groups during the 1996 campaign, has played a surprisingly small role in this year's midterm elections.

With just 11 days until the election, labor, business and other outside groups have put less money into these ads  which are often as slashing as regular political ads, but don't directly tell voters who to choose. The groups instead are either holding their fire, returning to traditional organizing techniques or putting more of their money into phone banks and direct mail to reach voters.

But even as there are fewer such commercials, some candidates are feeling the impact of multimillion-dollar media barrages trained directly on them.

Just ask some of the Nevada politicians who crossed Sheldon Adelson, a billionaire Las Vegas hotel magnate who tangled with the powerful county commission over plans for the Venetian, the 6,000-room Italian-themed mega-resort he is building on the Strip.

Now, as Election Day nears, Adelson's getting even.

Under the name of an organization dubbed the Committee for Fairness, Adelson is spending $2 million in an effort to unseat two Democratic members of the Clark County commission and defeat a third Democrat running for an open seat. Starting last week, the group unleashed a torrent of television advertising, mailings and phone calls that attack Commissioner Myrna Williams as "ethically bankrupt" and denounce Commissioner Erin Kenny for her business failure. "She bankrupted her business," one spot says of Kenny. "Now she's bankrupting us, too."

Issue advocacy has been an attractive and powerful tool for interest groups because they can spend unlimited sums from any source without having to comply with disclosure rules. But while political parties continue to pour millions into such advertising in their most critical races, issue advertising by outside groups is the dog that didn't bark this election  surprising some political analysts who had predicted the explosion of the technique during the 1996 campaign would continue.

"It's still nothing big and we're getting kind of late in the election cycle for something big to show up," said Democratic media buyer John Hutchens. "There isn't anybody who's doing a big, wholesale, 40-seats thing anywhere."

A study released last week by the Annenberg Public Policy Center, which monitors political advertising, estimated that $260 million to $330 million had been spent or earmarked for issue advocacy efforts in 1997-98, above the estimated $135 million to $150 million spent in 1995-96.

But much of this election cycle's spending involved massive efforts to influence legislation  for example, the tobacco bill, the global warming treaty, and telephone access charges  that took place well before Election Day. And campaign consultants and media buyers said in interviews that they do not see a level of activity in 1997-98 that matches the issue advocacy of two years ago.

Dan Weiss, political director of the Sierra Club, which has spent about $1.5 million on commercials in about 25 districts or states this year, attributed part of the lessened activity to the Monica S. Lewinsky scandal. "The upheaval over the last months . . . has probably made people more gun-shy," he said. "If you're looking at trying to do issue ads and you think, 'Oh my goodness, the bottom is going to drop out of the campaign,' or if you believe the candidate you're trying to defeat is going to lose anyway, one might question, why spend the money?"

Some groups, such as the business-backed Coalition and Americans for Limited Terms say they are devoting a greater percentage of their resources to direct mail rather than broadcasts because it is a better and more cost-effective way to target the most likely voters.

"We were worried about this low level of interest, and when you pay to broadcast something and two-thirds of the listeners aren't going to vote, you start to scratch your head," said Eric O'Keefe of Americans for Limited Terms, which is spending about $5 million this month on direct mail, television and radio in about 26 House districts. "The mail goes to people who have some history of voting. The ads go to everybody who has a television set."

The biggest outside group player during the 1996 campaign, the AFL-CIO, dramatically reduced its use of the technique  running about $5 million in issue advocacy ads this year compared with about $22 million two years ago, a decrease that has resulted in a correspondingly smaller issue advocacy effort by business. Instead, labor is concentrating more of its firepower on more traditional electoral techniques, such as get-out-the-vote efforts, that it hopes will make a difference in what is expected to be a low-turnout election.

Denise Mitchell, who oversees the union's issue advocacy effort, said the union looked, among other things, at the avalanche of outside group spending in the special election in California last January to fill the seat of the late Rep. Walter Holden Capps (D) and decided against devoting so much to issue advocacy. "We just heard it was so cluttered nothing was getting through," she said.

Still, the union was airing spots until earlier this week in Wisconsin, where Sen. Russell D. Feingold (D) has announced he did not want issue advocacy efforts on his behalf. The union spots blast Feingold's opponent, Rep. Mark W. Neumann, for voting against HMO reform. "Call Neumann and tell him to stop protecting the HMOs. And start protecting patients," the ad concludes.

The Coalition, an array of business groups that was formed in 1996 to respond to the union effort, has similarly scaled back, spending about $1 million on a combination of television and radio advertising and direct mailing, compared with $5 million during the last election cycle. The group will be active in about 15 districts compared to 41 last time.

As happened in 1996, in the closing days of the campaign, more and more issue advertising is popping up on television screens and blaring from radio dials across the country.

One new group supported by GOP moderates, the Foundation for Responsible Government, has spent more than $800,000 on television and radio advertising. During the primary season, the group targeted conservative GOP candidates; in the past few weeks, it has launched ads criticizing Nevada Democratic House candidate Shelley Berkely in her campaign against moderate Republican Don Chairez, and lauded Nevada GOP Senate candidate Rep. John Ensign, in a close race against incumbent Harry M. Reid (D).

Campaign for America, a group founded by investor Jerome Kohlberg that advocates reducing the impact of money in politics, is spending more than $400,000 to influence a close Kentucky Senate race between Reps. Jim Bunning (R) and Scotty Baesler (D).

"After big HMOs gave him thousands in contributions, Bunning flip-flopped and opposed HMO reform," the ad says. "Now Bunning is hunting for more money  still listening to special interests, not the people of Kentucky."

The Campaign for America ads call for Bunning's defeat and therefore don't count as issue ads. Instead, they are independent expenditures that must be reported to the Federal Election Commission.

One dramatic example of how a single group can unleash a torrent of issue advertising involves Rep. Frank Pallone Jr., a New Jersey Democrat facing a tough reelection race that has become even dicier in recent days, in part because of the entry of a new business-backed group called Americans for Job Security.

Starting last weekend, the group began running more than $1 million in television ads that blast Pallone for allegedly raiding the Social Security Trust Fund "to pay for welfare and other wasteful programs," raising taxes, and increasing his own pay after promising not to. One ad airing on CBS's "60 Minutes" cost $40,000, Pallone campaign officials said.

The spot shows a group of sleazy-looking men dealing cards around a poker table, as one, wearing heavy gold rings, rakes the chips in front of him. "Call Congressman Frank Pallone and tell him to keep his hands off Social Security and stop gambling with our future," concludes the ad, part of the group's $7 million issue advocacy effort in about 20 markets around the country.

After the Pallone campaign complained about the accuracy of the spot  and, it says, one station pulled it  Americans for Job Security struck back, increasing the amount of its spending from $1.2 million to $1.6 million.

"It's not against him. He shouldn't be so sensitive," Americans for Job Security Executive Director David Carney said of the spot. He said the ad was "100 percent accurate" and simply part of the group's effort to spread its message of "fiscal responsibility." The group, which was put together by the American Insurance Association, would not disclose the identities of its donors.

Pallone, whose own media budget of $750,000 is well below that of the blitz that Americans for Job Security has unleashed on him, asserts that the business group is attacking him because of his efforts to reform the HMO industry and that the allegation that he "raided Social Security" is "totally false."

"I've never seen this kind of issue advocacy on the New York network TV," he said. "I have to assume that this level of buy has some impact. How much I don't know. It's being shown in prime time and it's so much money."

In Nevada, the Adelson effort  which has spawned a counter-group called the Committee for Common Decency  is perhaps the most concentrated example this campaign season of "issue advocacy" and how its use has trickled down to the local level.

Callers who dial the toll-free number listed in the ads are connected to an operator who asks their name and address and then offers to patch them through to the candidate's office. "Did you want to connect to Myrna Williams's office and tell her to stop the corruption?" the operator asked a caller yesterday.

Andy Abboud, Adelson's director of government relations, said Adelson launched the effort because the commissioners were "doing everything in their power to slow down the project" because Adelson refused to give into demands that the hotel be unionized. Adelson, he said, "decided I can give this money to all these other entities [political parties] or I can spend the money on my own, to fight my fight the way I want to do it."

Williams campaign chief Mike Sullivan said Adelson's spending was astronomical, and that even in the most costly local races individual candidates rarely spend more than $400,000. "Nobody on the local level has ever done anything like this," he said. "Obviously, the impact is massive."